In-mold formed paper corner protector based on homogeneous flexible hinge structure

Abstract

The utility model relates to a kind of in-mold forming paper corner bead based on homogeneous toughness hinge structure, paper corner bead is made by core blank mould pressing, the core blank is formed by single-face corrugated board band in the way that preset value included angle is presented in corrugated ridge line direction and length direction, through multilayer continuous rotation winding and adhesion, at least one guide paper rope is equipped in the area where the core blank is bent into interior angle.This paper corner bead is wound by a complete single-face corrugated paper band, compared with traditional kraft paper paper corner bead, it uses less material, and the supporting structure of corrugation can greatly improve the compressive strength, with good buffering and damping effect.

Description

Technical Field

[0001] This utility model relates to the field of product packaging, and in particular to an in-mold forming paper corner protector based on a homogeneous toughness hinge structure. Background Technology

[0002] Existing paper corner protectors are mostly made using laminated paperboard bending or on-site winding and curing processes, which have inherent defects: the laminated structure relies on the adhesive interface and is prone to delamination when exposed to moisture. Some paper corner protectors, even those fixed with clips after folding, also suffer from weak bonding, resulting in fragile interlayer interfaces. When conventional paper corner protectors are bent while the paper is dry, fiber breakage occurs, forming hidden cracks that become stress concentration points, significantly reducing fatigue strength and impact toughness. With the implementation of plastic bans, EPE corner protectors, which offer better cushioning, higher density, and stronger protection, are being gradually phased out. Summary of the Invention

[0003] This utility model provides an in-mold formed paper corner protector based on a homogeneous toughness hinge structure, aiming to provide a novel paper corner protector structure and production process that can ensure strength while achieving environmentally friendly and efficient production.

[0004] This utility model provides an in-mold formed paper corner protector based on a homogeneous toughness hinge structure. The paper corner protector is molded from a core blank. The core blank is formed by continuously rotating and bonding multiple layers of single-sided corrugated cardboard strip at a preset angle between the corrugated ridge direction and the length direction. At least one guide paper rope is provided in the area where the core blank is bent into an inner corner.

[0005] As a further improvement of this utility model, the preset included angle is 90 degrees.

[0006] As a further improvement of this utility model, the single-faced corrugated cardboard tape includes a core paper layer and a face paper layer. The face paper layer is disposed on the outer layer of the core paper layer, and after the core blank is formed, the core paper layer of the outer single-faced corrugated cardboard tape contacts the face paper layer of the inner single-faced corrugated cardboard tape.

[0007] As a further improvement of this utility model, a polymer water-soluble adhesive is applied to the corrugated peaks of the single-sided corrugated cardboard strip, and the polymer water-soluble adhesive is applied between the outer core paper layer and the inner face paper layer.

[0008] As a further improvement of this utility model, a guide paper rope is provided every 50mm along the corrugated ridge line of the core blank.

[0009] As a further improvement of this utility model, the diameter of the guide paper rope is in the range of 0.8mm-1.2mm.

[0010] As a further improvement of this utility model, the material of the guide paper rope is kraft paper.

[0011] The beneficial effects of this utility model are: the paper corner protector is made of a complete single-sided corrugated paper strip, which uses less material compared with traditional kraft paper corner protectors. At the same time, the corrugated support structure can greatly improve the compressive strength and has a better cushioning and vibration reduction effect. Attached Figure Description

[0012] Figure 1 This is an overall drawing of the paper corner protector of this utility model; Figure 2 This is a side view of the core blank of this utility model; Figure 3 This is a side view of the paper corner protector of this utility model.

[0013] Reference numerals: 1-Single-faced corrugated cardboard strip, 2-Guide paper rope, 10-Face paper layer, 11-Core paper layer. Detailed Implementation

[0014] To make the objectives, technical solutions, and advantages of this utility model clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be noted that the terms "front," "rear," "left," "right," "upper," and "lower" used in the following description refer to directions in the accompanying drawings, while the terms "bottom surface," "top surface," "inner," and "outer" refer to directions toward or away from the geometric center of a specific component, respectively.

[0015] like Figure 1-3 As shown, this utility model provides an in-mold molded paper corner protector based on a homogeneous toughness hinge structure. The paper corner protector is molded from a core blank. The core blank is formed by continuously rotating and bonding multiple layers of single-sided corrugated cardboard strip 1 at a preset angle between the corrugated ridge direction and the length direction. At least one guide paper rope 2 is provided in the area where the core blank is bent into an inner corner.

[0016] As one embodiment of this utility model, the preset included angle is 90 degrees.

[0017] In another embodiment of this utility model, the single-faced corrugated cardboard strip 1 includes a core paper layer 11 and a face paper layer 10. The face paper layer 10 is disposed on the outer layer of the core paper layer 11, and after the core blank is formed, the core paper layer 11 of the outer single-faced corrugated cardboard strip 1 contacts the face paper layer 10 of the inner single-faced corrugated cardboard strip 1. The core paper layer 11 is composed of continuous M-shaped cardboard, and the face paper layer 10 is a smooth cardboard plane.

[0018] In another embodiment of this utility model, a polymer water-soluble adhesive is applied to the flute peaks of the single-sided corrugated cardboard strip 1, and the polymer water-soluble adhesive is applied between the outer core paper layer 11 and the inner face paper layer 10. After rotational winding to form a core blank of a certain thickness, a structure in which the face paper layer 10 and the core paper layer 11 are alternately arranged is formed, and then the inner and outer layers are bonded together by the polymer water-soluble adhesive to form a stable blank structure.

[0019] In another embodiment of this utility model, a guide paper rope 2 is provided at 50mm intervals along the corrugated ridge line of the core blank.

[0020] In another embodiment of this utility model, the diameter of the guide paper rope 2 is in the range of 0.8mm-1.2mm.

[0021] In another embodiment of this utility model, the material of the guide paper rope 2 is kraft paper.

[0022] This invention provides an in-mold formed paper corner protector based on a homogeneous toughness hinge structure. It consists of at least one continuous single-faced corrugated cardboard strip 1, wound in multiple layers on a plane with the corrugated ridge direction forming a 90-degree angle with the strip's length direction. During winding, a water-soluble adhesive is simultaneously applied to the corrugated peaks to bond each layer of corrugated cardboard, forming a single-faced corrugated paper wet-wound flat core blank of equal thickness. This core blank is then pressed and cured using an "L"-shaped mold. The single-faced corrugated cardboard strip 1 is a B-flute single-faced corrugated cardboard strip.

[0023] In the area where the core blank is to be bent into an inner corner, at least one guide paper rope 2 made of kraft paper is pre-embedded; during the molding process, the guide paper rope 2 absorbs the water-soluble adhesive in the core blank and undergoes plastic deformation, guiding the core blank material to flow and gather in an orderly manner towards the inner corner area; after final curing, the guide paper rope 2 is completely fused with the surrounding matrix, forming a high-toughness hinge structure with continuous paper components and no clear interface in the inner corner area.

[0024] The manufacturing process of this paper corner protector is as follows: First, a continuous B-flute single-sided corrugated paper strip is wound continuously at a certain angle. At the same time, a polymer water-soluble adhesive is roller-coated at the flute peaks of each layer of single-sided corrugated paper strip 1. The main components of this adhesive are PVA, acrylate, and bio-based starch ternary composite polymer water-soluble adhesive. The amount of adhesive applied is 20-30 g / m². 2 This forms an uncured, wet-wound core blank with a certain moisture content (approximately 30%-50%). When winding to the predetermined inner corner position, a guide paper rope 2 with a diameter of 0.8 mm to 1.2 mm is simultaneously wound in and positioned inside the core blank at intervals of 50 mm in the direction of the corrugated ridge line. The diameter of the guide paper rope 2 is preferably 1 mm. Subsequently, the entire soft core blank is quickly transferred into an L-shaped cavity mold preheated to 55-70 degrees Celsius. The mold is closed and pressure is applied. Under pressure, the core blank plastically flows and fills the cavity, with some moisture being expelled. During this process, the internal guide paper rope 2 absorbs moisture and adhesive, softens, and guides the material to gather orderly towards the inner corners. After holding the pressure for a certain period to stabilize the shape, the mold is opened and the component is removed. Finally, it passes through a drying channel to allow the adhesive to fully cure, resulting in the final product.

[0025] This invention employs a novel process—"wet core blank in-mold pressing"—completely different from the dry forming (lamination bending, dry winding) currently used in paper corner protector production. Using homogeneous kraft paper rope as the guide line, the resulting "tough hinge" structure effectively solves the problem of easy damage during bending; achieving 100% environmental consistency from main materials and auxiliary materials to the process, meeting green environmental protection requirements. This paper corner protector is made by winding a complete single-sided corrugated paper strip, using less material compared to traditional kraft paper corner protectors. Simultaneously, the corrugated support structure greatly improves compressive strength and provides better cushioning and vibration reduction.

[0026] The above description, in conjunction with specific preferred embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of the present invention, and all such modifications and substitutions should be considered within the protection scope of the present invention.

Claims

1. An in-mold formed paper corner protector based on a homogeneous toughness hinge structure, characterized in that, The paper corner protectors are molded from core blanks. The core blanks are formed by continuously rotating and bonding multiple layers of single-sided corrugated cardboard strips at a preset angle between the corrugated ridge direction and the length direction. At least one guide paper rope is provided in the area where the core blank is bent into an inner corner.

2. The in-mold formed paper corner protector based on a homogeneous toughness hinge structure according to claim 1, characterized in that, The default angle is 90 degrees.

3. The in-mold formed paper corner protector based on a homogeneous toughness hinge structure according to claim 1, characterized in that, The single-faced corrugated cardboard strip includes a core paper layer and a face paper layer. The face paper layer is disposed on the outer layer of the core paper layer. After the core blank is formed, the core paper layer of the outer single-faced corrugated cardboard strip comes into contact with the face paper layer of the inner single-faced corrugated cardboard strip.

4. The in-mold formed paper corner protector based on a homogeneous toughness hinge structure according to claim 3, characterized in that, A polymer water-soluble adhesive is applied to the corrugated edges of the single-sided corrugated cardboard strip, and the polymer water-soluble adhesive is applied between the outer core paper layer and the inner face paper layer.

5. The in-mold formed paper corner protector based on a homogeneous toughness hinge structure according to claim 1, characterized in that, One guide paper rope is provided every 50 mm along the corrugated ridge line of the core blank.

6. The in-mold formed paper corner protector based on a homogeneous toughness hinge structure according to claim 1, characterized in that, The diameter of the guide paper rope ranges from 0.8mm to 1.2mm.

7. The in-mold formed paper corner protector based on a homogeneous toughness hinge structure according to claim 1, characterized in that, The guide paper rope is made of kraft paper.

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